Hourican Associates Ltd | 04-11-2025

Most London loft conversions will require a Party Wall notice even if the works are Permitted Development. Below is a step-by-step, legally correct overview of when notices are needed, which notice(s) to serve, statutory time limits, neighbour responses, and how disputes are resolved.

When does a loft conversion trigger the Act?

Loft projects typically involve one or more notifiable items:

• Cutting into a party wall (e.g., inserting loft steels), raising/altering a party wall or removing a chimney breast attached to it → Section 2 (Party Structure) applies. (Legislation.gov.uk)
• Excavating for padstones/posts within 3m (and deeper than your neighbour’s foundations) or within 6m where the excavation intersects the 45° line from their foundations → Section 6 (Adjacent Excavation) applies.

If your design doesn’t bear on the party wall and doesn’t involve notifiable excavation, a notice may not be required—have a qualified surveyor confirm against your structural drawings.

Permitted Development vs Party Wall (different regimes)

Many lofts are PD, but PD rights do not remove Party Wall or Building Regulations duties. Typical PD limits for houses: 40m³ (terraced) / 50m³ (semi/detached) plus other conditions (e.g., not extending over the principal elevation).

Which notice(s) to serve and how long before works?

• Section 2: Party Structure Notice – at least 2 months before works affecting the party wall. Valid for 12 months. Early start is only with the neighbour’s written agreement. (Legislation.gov.uk)
• Section 6: Adjacent Excavation Notice – at least 1 month before excavation; the 14-day response rules mirror Section 2.
• Section 1: Line of Junction Notice – 1 month before building a new wall at/astride the boundary (lofts rarely need this).
• GOV.UK confirms the general 2 months to 1 year window for starting notified works and provides official letter templates.

What must the notice include?

Your notice must state the building owner’s name and address, nature/particulars of the works (attach plans/sections where relevant), and the proposed start date (after the correct notice period). Official templates are available and explicitly note you may only start earlier with written consent.

Electronic service: Notices/Awards can be served by email only if the recipient has consented in advance and supplied the email address (2016 Electronic Communications Order). Otherwise use permitted service methods under s.15.

Who must you notify?

You must notify all “Adjoining Owners”—that can include the freeholder and any leaseholder with a lease exceeding 1 year. If there is more than one owner or more than one affected property, you must notify all of them. (RICS)

Neighbour responses, disputes and access

• 14 days to respond. For Section 2/6 notices, no reply within 14 days = dispute deemed; the s.10 procedure starts. (RICS)
• Surveyor(s). Either appoint one Agreed Surveyor or one each. If a party fails to appoint within 10 days of a request, the other side may appoint on their behalf (s.10(4)). (Legislation.gov.uk)
• Award. Surveyor(s) issue a Party Wall Award covering method, protections and usually a Schedule of Condition (good practice, commonly included). (RICS)
• Appeal. Either party may appeal to the County Court within 14 days of service of the Award. (GOV.UK)
• Access. Statutory right of access for works “in pursuance of the Act” during usual working hours with 14 days’ written notice (s.8). (Legislation.gov.uk)

Typical loft scenarios (and the right notice)

• Rear dormer with steels into party wall; chimney breast removed: Section 2 Party Structure Notice (plus Schedule of Condition recommended).
• Mansard requiring parapet raise: Section 2 Party Structure Notice.
• Hip-to-gable with padstones within 3m and deeper than neighbour’s footings: Section 6 Adjacent Excavation Notice.

If more than one section applies, you may combine notices in one letter provided all required particulars are included (see the government example letters).

What to give your surveyor up front

• Structural drawings (steel bearings, posts/columns) and proposed sections.
• Foundation info (yours/known neighbour depths) for any Section 6 works.
• Ownership details (freeholder + any long leaseholder >12 months). (RICS)

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